API/ABI breakers for melodic

[mikeferguson]

This PR implements the following ABI/API breaking changes for Melodic with backwards compatability:

• update all occurences of min_in_place_rotational_vel with min_in_place_vel_theta. Affects RotateRecovery (RotateRecovery parameter names differ from TrajectoryPlannerROS parameter names #706) and TrajectoryPlannerROS (min_in_place_rotational_vel and min_in_place_vel_theta #487).

This PR also implements the following non-backwards-compatible ABI/API changes:

• unify parameter names of base_local_planner/dwa_local_planner (Unify parameters names for local planner (trivial change) #90)
  • dwa: min/max_rot_vel -> min/max_vel_theta to match base_local_planner
  • dwa: min/max_trans_vel -> min/max_vel_trans to match every other style of param
  • dwa: rot_stopped_vel -> theta_stopped_vel (undocumented parameter, updating to match other theta names)
  • Not addressing pdist_scale/path_distance_bias yet
• removes robot_pose_ekf (Drop robot_pose_ekf in Melodic? #701). We recommend using robot_localization instead.
• fixes reversed order of odom1 and odom4 parameters in the omni-directional model (Inconsistent odom_alpha1 and odom_alpha4 parameters between AMCL's diff and omni models? #499). At least in all of our tests, odom1 == odom4, so I don't think this will actually hurt anyone.

In addition to documenting the above, we need to update:

• dwa_local_planner: acc_lim_th -> acc_lim_theta (code was changed a long time ago, just wrong in wiki)

[mikeferguson]

This is ready for review -- I plan to work on the TF2 stuff tomorrow (I've finally got a working 18.04 box over here, with a gazebo sim to test in)

[mikeferguson]

I rebased to get around the merge conflict I just created -- once CI passes, I'll merge this in